CA2702382A1 - Protection system for subsea seawater injection pumps - Google Patents

Protection system for subsea seawater injection pumps Download PDF

Info

Publication number
CA2702382A1
CA2702382A1 CA 2702382 CA2702382A CA2702382A1 CA 2702382 A1 CA2702382 A1 CA 2702382A1 CA 2702382 CA2702382 CA 2702382 CA 2702382 A CA2702382 A CA 2702382A CA 2702382 A1 CA2702382 A1 CA 2702382A1
Authority
CA
Canada
Prior art keywords
pump
motor
fluid
pressurized fluid
pump system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA 2702382
Other languages
French (fr)
Other versions
CA2702382C (en
Inventor
Audun Grynning
Stein Vegar Larsen
Geir Inge Olsen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Aker Solutions AS
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of CA2702382A1 publication Critical patent/CA2702382A1/en
Application granted granted Critical
Publication of CA2702382C publication Critical patent/CA2702382C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00Pumping installations or systems
    • F04D13/02Units comprising pumps and their driving means
    • F04D13/06Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/08Units comprising pumps and their driving means the pump being electrically driven for submerged use
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00Details, component parts, or accessories
    • F04D29/08Sealings
    • F04D29/10Shaft sealings
    • F04D29/106Shaft sealings especially adapted for liquid pumps
    • F04D29/108Shaft sealings especially adapted for liquid pumps the sealing fluid being other than the working liquid or being the working liquid treated
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00Pumping installations or systems
    • F04D13/02Units comprising pumps and their driving means
    • F04D13/06Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/08Units comprising pumps and their driving means the pump being electrically driven for submerged use
    • F04D13/086Units comprising pumps and their driving means the pump being electrically driven for submerged use the pump and drive motor are both submerged
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00Details, component parts, or accessories
    • F04D29/08Sealings
    • F04D29/10Shaft sealings
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/8593Systems
    • Y10T137/85978With pump
    • Y10T137/86035Combined with fluid receiver

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Jet Pumps And Other Pumps (AREA)

Abstract

This invention relates to a pump system, especially for boosting the flow rate of a fluid through a pipe (1, 2, 6), comprising a pump positioned in a pump chamber (10) for pumping at a chosen rate, and a motor driving said pump, the motor being positioned in a chamber (9) being provided with a pressurized fluid, the pressure of which being higher than the pressure in the pump chamber, the motor and the pump chambers being separated by a seal (8), the seal allowing a leakage of said pressurized fluid between them, wherein the pressurized fluid is acceptable to the pump environment and the system comprises a discharge branch line (3) coupled to the pipe(6) and positioned downstream from said pump, the discharge branch line having an outlet into the environment.

Description

PROTECTION SYSTEM FOR SUBSEA SEAWATER INJECTION PUMPS.

General description Pumps will typically have to be operated above a minimum flow rate in order to avoid creating unstable behaviour, overheating and consequently pump breakdown. In order to obtain this protection of the pump at low flow demands, a minimum flow arrangement is included. Such arrangement will typically include routing flow back from the outlet to the inlet through a throttling device. Such by-pass can be active continuously or enabled by a valve activated at low flow or high pressure at the outlet.
A centrifugal pump applied for subsea raw sea water injection can have a minimum flow arrangement of the same kind as typically used topsides.
A subsea pumping system is designed to move fluid, i.e. liquid and/or gas from one location to another. This may be achieved by using a pump.. Common for all processes that involve moving of fluids is that the process requires added energy. This energy is typically added by using some kind of motor and fed to the pump through a shaft, e.g. in centrifugal pumps and rotodynamic pumps as described in GB1218023, US3468259 and US6447245. Such a solution therefore requires some kind of shaft sealing system.
The objective of the shaft sealing system is to prevent mixing of the fluids inside the motor and in the pump. Since intrusion of seawater may cause degradation or destruction of the motor internals, especially in the case where the motor is electric, an over-pressure is applied in the motor. The higher pressure in the motor will cause a leakage across the shaft seal from the motor to the pump, preventing ingress of fluid from the pump to the motor. Therefore, the leaking motor fluid will mix with the seawater flowing through the pump.

Pumps have a limited operating envelope with regards to flow and head, i.e. a certain minimum amount of liquid must flow through the pump at all times to avoid overheating and excessive vibrations. To stay within the operating envelope during any mode of operation, a pump protection system is necessary, ensuring a certain minimum amount of flow through the pump. A typical arrangement of such a minimum flow arrangement is shown in figure 1.

Also, the flow through the pump will be contaminated by the leaking fluid from the motor across the shaft sealing system. This may pose a problem because of restrictions in the leakages into the environment and may require cleaning of the pumped fluids or reduction of the leaks. It is therefore an object of the present invention to simplify the pump protection system needed in subsea pumping systems, and also reduce the contaminations in the pumped fluid.
The present invention obtain these objects by providing a simpler pump protection system compared with the traditional recirculation system for a pump system designed for boosting seawater to an injection well or for other purposes. This is obtain by using a pump system as described above and specified as stated in the independent claim.
The invention is thus based on the concept of using an environmental friendly fluid in the motor. Environmentally friendly fluids being defined as fluids being allowed by existing regulations, e.g. being non-toxic in the environment it is introduced. By using a fluid in the motor that is acceptable to the pump environment, the fluid flow can be dumped into the environment without causing any threat. The invention also provides a system where the pump is used within the optimal range of flow rates as the pumped fluid as well as the pressurized fluids leaked from the motor may be circulated back into the surroundings without polluting the environment. Thus improved protection for the pump is obtained.
The invention will be described below with reference to the accompanying drawings, illustrating the invention by way of example.
Figure 1 illustrates a typical minimum flow arrangement according to the known art.
Figure 2 illustrates the system according to the invention Current subsea pumping systems utilize conventional electric motors with windings that have connections that are not fully insulated towards the environment, filled with dielectric oil where said oil act as an additional insulator. According to environmental rules and regulations, emission of such dielectric oil to the environment is not allowed.
For systems utilizing such fluids, a closed minimum flow loop for pump protection must be used as indicated in figure 1.

In a closed loop, where the same water is being recirculated, the energy added by the pump into the fluid would cause the fluid, and hence the pump, to overheat and finally cause breakdown. The closed loop solution therefore requires an orifice/choking device, piping and valves to form the closed loop, and a cooler to avoid overheating of the re-circulating fluid in the closed loop.

The present invention as explained in the following will significantly reduce the size and number of components necessary, ultimately leading to lower cost, weight and complexity of a subsea pumping system.

Referring to figure 2 the pump unit (8,9,10,11) generates a now from the pump inlet (1) to the discharge pipe/line (2,6). The receiving reservoir has a flow/head characteristic. If the resistance of the receiving reservoir is outside the pump operating envelope, sufficient flow through the discharge pipe (6) can not be established. The system must therefore ensure continued operation by establishing a flow through a discharge branch line (3) positioned downstream the outlet from said pump and being separated from the pump by a fluid conduit (2). According to the preferred embodiment of the invention the discharge branch line is controlled by opening the valve (4) causing the discharge flow to be routed directly to sea through a choking device (5). The choking device (5) may be a part of the valve (4) itself or be a separate choking device upstream or downstream a valve without choking function. The choking device (5) is designed so that when the valve (4) is open, the pump is ensured sufficient flow regardless of resistance of the receiving reservoir (closed valve or other cause of high resistance in the discharge pipe (6).
The system incorporates a measuring or control system which in a per se known way monitors the conditions in the discharge pipe and possibly other conditions therein, and controls both pump speed and valves in order to maintain the pump in the optimum operation range. This may also be performed by automatic opening of the valves at a chosen motor resistance or other pump protection methods.

Routing of pump discharge fluid directly to sea as described herein is only possible, i.e.
allowed, if said fluid is environmentally friendly. This is ensured by the arrangement described below.
According to the preferred embodiment of the invention the pump unit includes a motor chamber (9), preferably containing an electrical motor, which is separated from the pump chamber(s) (10) by the use of a sealing system (8) through which the shaft or power transmission (11) from the motor to the pump is lead. The motor chamber (9) is separated from the pump chamber (10) containing a pump, e.g. a centrifugal pump, using one or several additional chambers. The motor chamber (9) is fed by a pressurized, environmental friendly seal fluid, i.e. a fluid that is acceptable to the pumped medium and the environment, through a line (7) from a supply either located subsea or topside. The motor fluid supply, typically made up by a mixture of water and glycol (or other ingredients that ensure sufficient corrosion resistance), shall ensure a higher pressure in the motor chamber (9) than in the pump (10) to prevent ingress of seawater into the motor (9). The sealing system (8) is made to prevent exchange of fluid between the chambers but will not entirely seal the chambers. The higher pressure in the motor will therefore cause a leakage through the seal system (8). The leakage of the motor fluid will mix with the seawater coming from the pump inlet (1).

This way it is possible to secure a minimum flow through a raw sea water injection pump by circulation, at least a portion of the total flow back to sea though a remote controlled valve. Flow back into the sea is obtained through a discharge branch line preferably including a valve, e.g. a choke, which may be controlled topside, involve local pressure sensor etc for controlling the flow. The valve can be combined with a fixed orifice for providing improved control of the flow. As stated above the circulation to sea can be done in an environmentally friendly way due to using environmental friendly fluid as barrier fluid and cooling fluid in the motor. In order to avoid electrical conduction through the pressurized fluid in the motor the electric motor has fully insulated winding, thus making it possible to accept water based environmentally 5 friendly fluid as cooling fluid.

The present invention is mainly aimed at the purpose of injecting sea water into a well using a rotodynamic or positive displacement pump driven by an electric motor, but other uses, e.g. involving an hydraulic motor, may be contemplated. The orifice and valve may be chosen from any available types suitable for the specific use. As is evident from the discussions above it is also important that the pumped fluid is acceptable to the environment as it is discharged into the environment when the pressure in the discharge pipe is too high.

Claims (10)

1. Pump system, especially for boosting the flow rate of a fluid through a pipe, comprising a pump positioned in a pump chamber for pumping at a chosen rate, and a motor driving said pump, the motor being positioned in a chamber being provided with a pressurized fluid, the pressure of which being higher than the pressure in the pump chamber, the motor and the pump chambers being separated by a seal, the seal allowing a leakage of said pressurized fluid between them, wherein the pressurized fluid is acceptable to the pump environment and the system comprises a discharge branch line coupled to the pipe and positioned downstream from said pump, the discharge branch line having an outlet into the environment.
2. Pump system according to claim 1, wherein said motor is an electrical motor and said pressurized fluid is a water based fluid.
3. Pump system according to claim 2, wherein the pressurized fluid in the motor is a cooling fluid for cooling said motor.
4. Pump system according to claim 1, wherein said pressurized fluid is a water based barrier fluid.
5. Pump system according to claim 1, wherein said overflow line comprises a valve for regulating the flow there through.
6. Pump system according to claim 5, wherein said valve is a choke.
7. Pump system according to claim 5, wherein said discharge branch line comprises an orifice for limiting the flow rate to a chosen rate.
8. Pump system according to claim 1, wherein said pressurized fluid is a mixture of water and glycol.
9. Pump system according to claim 1, wherein the motor is an electrical motor comprising insulated windings and the pressurized fluid is electrically conductive.
10. Pump system according to claim 1, comprising a control system for monitoring the pump resistance and controlling the flow through the discharge line so as to maintain the pump rate at a chosen minimum rate.
CA2702382A 2007-10-09 2008-10-07 Protection system for subsea seawater injection pumps Expired - Fee Related CA2702382C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
NO20075118A NO327557B2 (en) 2007-10-09 2007-10-09 Pump protection system
NO20075118 2007-10-09
PCT/NO2008/000356 WO2009048336A1 (en) 2007-10-09 2008-10-07 Protection system for subsea seawater injection pumps

Publications (2)

Publication Number Publication Date
CA2702382A1 true CA2702382A1 (en) 2009-04-16
CA2702382C CA2702382C (en) 2016-04-05

Family

ID=40293660

Family Applications (1)

Application Number Title Priority Date Filing Date
CA2702382A Expired - Fee Related CA2702382C (en) 2007-10-09 2008-10-07 Protection system for subsea seawater injection pumps

Country Status (9)

Country Link
US (1) US8556600B2 (en)
CN (1) CN101821512B (en)
AU (1) AU2008311473B2 (en)
BR (1) BRPI0818365B1 (en)
CA (1) CA2702382C (en)
GB (1) GB2466146B (en)
MY (1) MY157762A (en)
NO (1) NO327557B2 (en)
WO (1) WO2009048336A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO332972B1 (en) * 2010-06-22 2013-02-11 Vetco Gray Scandinavia As Pressure Control System for Engine and Pump Barrier Fluids in a Submarine Engine and Pump Module
NO332973B1 (en) * 2010-06-22 2013-02-11 Vetco Gray Scandinavia As Pressure control system for motor and pump barrier fluids with differential pressure control
RU2608662C2 (en) * 2011-03-15 2017-01-23 Акер Сабси АС Pressure booster for underwater operations
CN102788026B (en) * 2011-05-16 2015-07-08 梁嘉麟 Anti-leaking sealing method of full-sealing liquid pump of with detachable motor stator during operation
GB2535124B (en) * 2013-12-23 2020-05-06 Vetco Gray Scandinavia As Method and system for supplying barrier fluid in a subsea motor and pump assembly

Family Cites Families (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1293390B (en) * 1957-05-28 1969-04-24 Commissariat Energie Atomique Device for sealing a centrifugal compressor used to compress a caustic, harmful and / or valuable gas
CH501839A (en) 1966-11-12 1971-01-15 Zabrzanska Fabryka Masz Gornic Dynamic pump
GB1218023A (en) 1967-07-07 1971-01-06 Weir Pumps Ltd Formerly G & J Improvements in or relating to rotodynamic pumps
DE2341500C3 (en) * 1973-08-16 1980-08-21 Siemens Ag, 1000 Berlin Und 8000 Muenchen Electrical contact arrangement with a contact liquid
FR2348595A1 (en) * 1976-04-15 1977-11-10 Anvar ROTATING-LINEAR HYBRID MOTOR
US4487299A (en) * 1982-03-09 1984-12-11 Trw Inc. Protection apparatus for liquid-filled submergible motors and the like
GB8921071D0 (en) * 1989-09-18 1989-11-01 Framo Dev Ltd Pump or compressor unit
US4997340A (en) * 1989-09-25 1991-03-05 Carrier Corporation Balance piston and seal arrangement
US5101128A (en) * 1990-08-23 1992-03-31 Westinghouse Electric Corp. System and method for cooling a submersible electric propulsor
US5673721A (en) * 1993-10-12 1997-10-07 Alcocer; Charles F. Electromagnetic fluid conditioning apparatus and method
US5549447A (en) * 1995-08-21 1996-08-27 Mcneil (Ohio) Corporation System for cooling a centrifugal pump
US5795135A (en) * 1995-12-05 1998-08-18 Westinghouse Electric Corp. Sub-sea pumping system and an associated method including pressure compensating arrangement for cooling and lubricating fluid
GB9612201D0 (en) 1996-06-11 1996-08-14 Sweepax International Limited Rotodynamic pump
US6100616A (en) * 1997-10-16 2000-08-08 Camco International, Inc. Electric submergible motor protector
JP4644406B2 (en) * 1999-10-04 2011-03-02 ローレンス ポンプ インコーポレイテッド Underwater motor with shaft seal
JP3475174B2 (en) * 2000-02-10 2003-12-08 東芝テック株式会社 Electric pump
DE10024955A1 (en) * 2000-05-22 2001-11-29 Richter Chemie Tech Itt Gmbh Centrifugal pump with magnetic coupling
JP2002250294A (en) * 2001-02-21 2002-09-06 Nikkiso Co Ltd Centrifugal pump
US6497556B2 (en) * 2001-04-24 2002-12-24 Cdx Gas, Llc Fluid level control for a downhole well pumping system
JP2002327696A (en) * 2001-04-27 2002-11-15 Ebara Corp Liquid sealed submerged motor pump
US6688860B2 (en) 2001-06-18 2004-02-10 Schlumberger Technology Corporation Protector for electrical submersible pumps
US6666664B2 (en) * 2002-02-15 2003-12-23 Schlumberger Technology Corporation Technique for protecting a submersible motor
GB0204139D0 (en) * 2002-02-21 2002-04-10 Alpha Thames Ltd Electric motor protection system
CN100335795C (en) * 2002-05-07 2007-09-05 Emu潜水泵有限公司 Driving motor, especially for a pump
GB2388404B (en) * 2002-05-09 2005-06-01 Dana Automotive Ltd Electric pump
NO323324B1 (en) * 2003-07-02 2007-03-19 Kvaerner Oilfield Prod As Procedure for regulating that pressure in an underwater compressor module
US7341436B2 (en) * 2003-09-04 2008-03-11 Lawrence Pumps, Inc. Open face cooling system for submersible motor
US7654315B2 (en) * 2005-09-30 2010-02-02 Schlumberger Technology Corporation Apparatus, pumping system incorporating same, and methods of protecting pump components
US20080260539A1 (en) * 2005-10-07 2008-10-23 Aker Kvaerner Subsea As Apparatus and Method For Controlling Supply of Barrier Gas in a Compressor Module
NO324577B1 (en) * 2005-11-11 2007-11-26 Norsk Hydro Produksjon As Pressure and leakage control in rotary compression equipment
US7665975B2 (en) * 2005-12-20 2010-02-23 Baker Hughes Incorporated Seal section oil seal for submersible pump assembly
US7741744B2 (en) * 2006-03-27 2010-06-22 Schlumberger Technology Corporation System and method for protecting a submersible motor
US20090134719A1 (en) * 2006-04-14 2009-05-28 Ciiis, Llc Electric motor containing ferromagnetic particles
US7530391B2 (en) * 2006-05-31 2009-05-12 Baker Hughes Incorporated Seal section for electrical submersible pump
DE102006026678A1 (en) * 2006-06-02 2007-12-06 Laing, Oliver circulating pump
DE102006040048A1 (en) * 2006-08-26 2008-02-28 Wilo Ag Motor centrifugal pump, particularly immersion pump, comprises coolant pump driven by electric motor, where pump circulating coolant of electric motor and impeller is driven by electric motor
DE102007007559A1 (en) * 2007-02-15 2008-10-09 Siemens Ag Electric machine with ferrofluid components
NO330192B1 (en) * 2007-04-12 2011-03-07 Framo Eng As Fluid Pump System.
US8221092B2 (en) * 2008-10-31 2012-07-17 Baker Hughes Incorporated Downhole electrical submersible pump seal
DE102008064099B4 (en) * 2008-12-19 2016-05-04 Bühler Motor GmbH Centrifugal pump with a fixed axis

Also Published As

Publication number Publication date
GB2466146A (en) 2010-06-16
CA2702382C (en) 2016-04-05
WO2009048336A1 (en) 2009-04-16
BRPI0818365B1 (en) 2020-03-03
CN101821512A (en) 2010-09-01
AU2008311473A1 (en) 2009-04-16
AU2008311473B2 (en) 2013-05-02
CN101821512B (en) 2012-10-24
NO327557B1 (en) 2009-08-10
US8556600B2 (en) 2013-10-15
GB201004695D0 (en) 2010-05-05
MY157762A (en) 2016-07-15
GB2466146B (en) 2012-09-05
NO327557B2 (en) 2013-02-04
US20100239442A1 (en) 2010-09-23
BRPI0818365A2 (en) 2015-04-07
NO20075118L (en) 2009-04-14

Similar Documents

Publication Publication Date Title
CA2702382C (en) Protection system for subsea seawater injection pumps
AU2013357653B2 (en) Cooling arrangement of a pump intended for pumping a liquid
US8523540B2 (en) Fluid pump system
KR102565709B1 (en) Pump drive unit for conveying a process fluid
US20140241907A1 (en) High pressure water injection pump system
US7845477B2 (en) Automotive drive comprising a water-based retarder
EP2025937B1 (en) Reciprocating pump
RU2004107579A (en) HYDRAULIC LIFT WITH A HYDRAULIC ACCUMULATOR, AND ALSO WAY OF CONTROL AND REGULATION OF SUCH LIFT
CN101938191B (en) Dry-submarine dual-purpose motor system
AU2011268633B2 (en) Combined barrier and lubrication fluids pressure regulation system and unit for a subsea motor and pump module
CN110858745A (en) Cooling device and method for submarine motor
CN108105114A (en) A kind of backwash type canned motor pump with metering pump for pumping the medium containing particulate matter
JP2005002977A (en) Waterproof construction of submersible pump
JP6805065B2 (en) Submersible pump and submersible pump system using it
CN205407562U (en) Converter cooling system and wind generating set
CN101896687B (en) Subsea valve
CN113765277B (en) Dry-wet dual-purpose efficient operation motor and method and application thereof
JP2002138940A (en) Inline type pump-reversing hydraulic turbine
NO345592B1 (en) Subsea motor and pump assembly and its use in a subsea desalination plant
WO1983001660A1 (en) Pump system for placing in explosively dangerous locations on board a tanker
JP2018178856A (en) Pump device
IE960112A1 (en) Mechanical seals

Legal Events

Date Code Title Description
EEER Examination request

Effective date: 20130906

MKLA Lapsed

Effective date: 20181009